The bike is a GMC Denali (let's not get into that) and, having already lost the front mech shifter due to incredibly poor construction, I am completely dissatisfied with the Shimano Revos and ready for change. My university bike shop has a Parts Graveyard which means nearly any kind of shifter I can scrape from there is absolutely free--so this only leaves out brifters.

What type of shifter would be most effective for my short tours on this bike? I spend almost all my time on ~50 mile rides in the drops, so imagine that I would do similarly for 80-90 miles in a day (incredibly comfortable on this beast). I would like to minimize time that my hands are off the bars. That means bar ends, stem, and finger/thumb shifters right? Feelings on these types for touring?

As a specific question, which would be the most effective (combined with a properly adjusted mech) at "snapping" right into gear?

And then, I remember reading that DT and thumb shifters were friction...but friction works on indexed derailleurs just fine right?